At its Worldwide Developers Conference starting Monday, the company is expected to unveil its push to change how people buy and listen to music. Apple aims to counter the slowdown in music downloads—a business it pioneered more than a decade ago with iTunes—with a new subscription-based streaming service and an ad-supported online-radio offering.

On-demand streaming music services such as Spotify and Internet-radio provider Pandora have been around for years and boast tens of millions of users. But the audience remains something of a niche. Apple hopes to change that by bringing streaming music to casual listeners.

“No one has cracked that nut,” said Dan Cyan, senior director of media and content for research firm IHS.

Apple is expected to announce a $10-a-month service that will let users listen to any song or album they choose—as if they had an iTunes library with tens of millions of songs. It is also expected to revamp its free online-radio efforts with a battery of channels programmed like traditional radio stations, featuring high-profile personalities.

The company is expected to promote the service with a lengthy trial period and a major advertising campaign.

The new music strategy is one of many announcements expected at the annual conference that draws about 5,000 Apple partners and outside developers to the Moscone Center in San Francisco. As in most years, Apple will use the event to unveil new features of its iOS software for iPhones and iPads, as well as its Mac operating system.

One thing likely to be missing, however, is a new Apple TV set-top box. Apple has been working on a new device and had considered unveiling it at the conference, but decided not to include it in the keynote presentation Monday, according to a person familiar with Apple’s plans.

The conference, commonly known as WWDC, is more technical and less flashy than Apple’s hardware launches. But the innovations typically underpin the company’s future technology.

Last year, for example, the company introduced Swift, a new programming language widely praised by developers as a simpler way to create apps for Apple devices.

This year, Apple is expected to focus on streamlining and improving the stability of its iOS software for iPhones and iPads that has grown bloated over the years, according to people familiar with Apple’s plans.

There are expected to be new features, too, including the ability to multitask, or have more than one app open on a screen at a time. Multitasking is especially important as Apple pushes iPads into the workplace.

The new mobile software is also expected to include revamped Maps features, including directions featuring mass-transit options. Google Inc. has offered such a feature on its maps for several years.

Apple news site 9to5Mac.com has reported that Apple plans a new iOS feature called Proactive, similar to Google Now, the search giant’s service that anticipates a user’s needs based on information in his email and calendar.

Apple has said it would unveil a new software kit for developers making apps for its Watch.
Jeff Williams,
Apple’s senior vice president of operations, said at a conference last month that the new tools will allow developers to create apps that run directly on the Watch and can use the device’s sensors.

Currently, Apple Watch apps run on the iPhone, causing some apps to perform slowly. The ability to access the Watch’s processing power and sensors is expected to improve the third-party apps available for the Watch.